Demonstration apparatus



Feb. 20, 1934. J |NNEY 1,947,605

DEMONS THAT I ON APPARATUS Filed Dec. 50, 1952 IIIIIIIIIIIIIIIIfl/II I l V TOR- I5 21 BY W ATTORN EYS,

Patented Feb. 20, 1934 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to demonstration apparatus and has for an object an apparatus for demonstrating the sand flotation process for cleaning coal to prepare the same for 3 market.

In the sand flotation process of cleaning coal, slate and other impurities are separated from coal by a washing process based on the difference between the specific gravity of coal and the specific gravity of the impurities. The mixture of coal and impurities is introduced into a mixture of water and sand which is of higher specific gravity than the coal, but of lower specific gravity than the impurities. The impurities sink through the sand and water mixture while the coal floats and is thus separated from the impurities.

An apparatus embodying the present invention consists essentially of a transparent tank having an inlet near the upper end and two outlets, one at a slightly higher level than the inlet and the other at the bottom of the tank. The two outlets are connected with the suction side of a pump and the inlet is connected with the pressure side of the pump, thus providing means for circulating liquid through the tank. The circulating liquid for the system consists of a translucent solution of zinc chloride or other suitable material in water having a higher specific gravity than coal, but a lower specific gravity than the usual impurities of coal such as slate and the like.

A suitable amount of coal particles and rock particles is introduced into the solution which is caused to circulate through the system by operation of the pump, the level of the solution in the tank being so maintained that the upper outlet is partially exposed to atmosphere. Zinc chloride solution containing both coal and rock particles is introduced into the tank through the inlet and the coal being of less specific gravity than the solution floats on the solution over to the upper outlet and is discharged therethrough with some of the solution while the rock particles drop to the bottom of the tank and escape through the bottom outlet with some of the solution. The two out let streams are then mixed and the mixture is supplied to the pump for recirculation.

In its operation, the apparatus simulates the sand flotation process of cleaning coal. The transparence of the tank and the translucence of the solution render visible the simulated process. Air from the atmosphere is drawn into the circulating system through the upper tank outlet and produces infinitesimal bubbles in the solution, thus giving the appearance of sand in the solution stream entering the tank.

Other objects, novel features and advantages of this invention will be apparent from the fol- 0 lowing specification and accompanying drawing, wherein:

Fig. 1 is a perspective view of an apparatus embodying the invention;

Fig. 2 is a section on the line 2--2 of Fig. 3; '65

Fig. 3 is a section on the line 33 of Fig. 2;

Fig. 4 is a perspective view of the tank, and

Fig. 5 is an elevation partially broken away of the pump.

A cabinet 10 has a substantially triangular opening in its front wall and behind this opening there is arranged a similarly shaped tank 11 having glass front and rear walls. The side and bottom edges of the glass walls are received in grooves in a frame 12 supported from the shelf 13, the frame forming the end walls of the tank. The frame is of greater width than the tank and supports a plurality of electric lamps 12a behind the rear wall of the tank.

The tank is provided with an inlet pipe 14 which enters the tank near the top thereof and leads from the outlet of a pump 15. The tank is also provided with two outlet pipes 16 and 17, the former leading from the upper part of the tank and the latter leading from the lower 35 part of the tank and both discharging into a conduit 18 leading to the inlet of the pump 15. The end of the pipe 16 is arranged at a slightly higher level than the end of the pipe 14. The propeller 19 of the pump consists of four suitably angled blades enclosed by a cylindrical shroud 20 fastened to the ends of the blades. The front edge of the shroud 20 extends into an annular recess 21 around the inlet port. The propeller shaft is provided with a driving pulley 22 and a belt 23 transmits power from the motor 24 to the pulley 23.

The tank and pipes are filled with a translucent solution of zinc chloride or other similar material in water and a mixture of coal particles and stone particles is introduced into the tank, the solution being of higher specific gravity than the coal, but of lower specific gravity than the rock. The level of the solution in the tank is such that the end of the pipe 14 is completely covered While the end of thepipe 16 is partially uncovered. Operation of the pump 15 effects circulation of the solution through the pump and the various pipes. The pump delivers a mixture of coal and rock particles in the solution through the pipe 14 into the tank near the top, but below the level of the solution in the tank. The coal particles float on the surface of the solution in the tank while the rock particles sink through the solution to the bottom of the tank. A stream of solution containing coal particles is discharged from the tank through the pipe 16 while a stream of solution containing rock particles is discharged from the tank to the pipe 17.

The two streams are joined in the pipe 18 and solution containing both rock and coal particles is supplied to the pump 15 for recirculation. Also, air is drawn in through the pipe 16 and is distributed throughout the solution in minute bubbles and gives the appearance of sand upon discharge into the tank through the pipe 14. The shroud 20 rotates with the propeller and prevents passage of rock and coal particles between the ends of the propeller blades and the pump housing, thereby preventing grinding action of the propeller on the rock and coal particles passing through the pump, and thereby preventing disintegration of the particles.

A reflector is arranged obliquely over the top or the tank to permit an observer to View the surface of the liquid in the tank. Also, the front wall of the tank slopes so that the lower portion of the tank is of less thickness than the upper portion, thus causing some of the rock particles to contact with this wall and slide along it as they descend through the solution. Vents 26 and 27 are provided in the frame 12 for permitting free air circulation to prevent overheating of the cabinet by the electric lamps contained therein. The electric lamps 12a together with the lamps 28 illuminate the tank and make visible the separation of the coal and rock particles.

The cabinet is provided with an electric amplifying system having speakers 29 arranged in the upper portion of the cabinet. The amplifier is connected with a phonograph arranged in the cabinet, but not shown in detail in the drawing, the phonograph being provided for the purpose of presenting an audible description of process and the advantages of coal pr pared by by the sand flotation process. Also, an illuminated advertising monogram or the like is provided at 30, the illumination being effected by the lamp 31.

I claim:

1. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles but of lower specific gravity than the rock particles, means for circulating said liquid and particles through said tank, said means comprising an inlet and an outlet in the upper portion of the tank, an outlet from the lower portion of the tank, a pump,

and connections from said outlets and said inlet to said pump.

2. In a device of'the character prescribed for demonstrating the sand fiotation process of cleaning. coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles but of lower specific gravity than the rock particles, means for circulating said liquid and particles through said tank, said means comprising an inlet in the upper portion of the tank and an outlet at a higher level than said inlet, said outlet being partially above the level of liquid in the tank, and an outlet from the lower portion of the tank, a pump and connections from said outlets and inlet to said pump.

3. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles but of lower specific gravity than the rock particles, a pump, an inlet pipe leading from said pump into the upper portion of said tank, an outlet pipe leading from a higher level than the inlet pipe to said pump said outlet being partially above the level of the liquid in said tank, and an outlet from the lower portion of the tank leading to said pump.

l. In a device of the character described for demonstratiing the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being or" higher specific gravity than the coal particles but of lower'specific gravity than the rock particles, illuminating means in the rear of said tank, means for circulating said liquid and particles through said tank, said means comprising an inlet and an outlet in the upper portion of the tank, an outlet irom the lower portion of the tank, a pump, and connections from said outlets and said inlet to said pump.

5. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles but of lower specific gravity than the rock particles, illuminating means in the rear of said tank, means for circulating said liquid and particles through said tank, said means comprising an inlet in the upper portion of the tank and an outlet at a higher level than said inlet, said outlet being partially above the level of the liquid in said tank, and an outlet from the lower portion of the tank, a pump, and connections from said outlets and inlet to said pump.

6. In a device of the character'described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles but of lower specific gravity than the rock particles, illuminating means in the rear of said tank, a pump, an inlet pipe leading from said pump into the upper portion of said tank, an outlet pipe leading from a higher level than the inlet pipe to said pump, said outlet being partially above the level of liquid in said tank, and an outlet from the lower portion of the tank leading to said pump.

7. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank of less crosssection at its bottom than at its top, said tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles and of lower specific gravity than the rock particles, means for withdrawing liquid from both the upper portion and lower portion of the tank and introducing said liquid under pressure into the upper portion of said tank below the level of liquid in the tank.

8. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles and of lower specific gravity than the rock particles, outlets from the upper and lower portions of said tank, and an inlet at the upper portion of the tank, a pump, connections from said outlets and said inlet to said pump, said pump having a propeller comprising a plurality of blades, and a cylindrical shroud surrounding said blades and being connected to the ends thereof.

9. In a device of the character described for demonstrating the sand flotation process of cleaning coal, a transparent tank containing translucent liquid, coal particles and rock particles, said liquid being of higher specific gravity than the coal particles and of lower specific gravity than the rock particles, means for circulating said liquid and said particles through said tank, said means comprising an inlet in the upper portion of the tank and an outlet at a higher level than said inlet and being partially above the level of the liquid in said tank, an outlet from the lower portion of the tank, a pump, and connections from said outlets and inlet to said pump.

ROBERT J. LINNEY. 

